The disclosure concerns, according to a first aspect, a method for zone based detection of vehicles and a system for performing said method.
Systems and methods for automatic controlling passages of objects, typically vehicles, into and/or out from certain geographic areas have been developed during the recent decades, and systems and methods based on Global Navigation Satellite Systems (GNSS) technology are prevailing.
Satellite based road tolling systems are rapidly growing in number due to their versatility and flexibility. It allows for an advanced time/distance/place concept where policy makers can adjust price and tolling zones to best fit their objectives. Non-repudiation of the tolling statement is a very important aspect of the toll system. This includes both proving that the toll statement is genuine and proving that the system correctly identifies vehicles travelling in and out of tolling zones.
Even if the average performance and availability of GNSS systems today are very good, there will still be situations where the tolling system may be mislead by erroneous position estimates from the GNSS system. In particular in geographical areas where parts of the sky are obstructed by natural or man-made objects, this may be of great concern.
GNSS based tolling and the system model in FIG. 1 is described by international standards. Of most relevance to the disclosed method and system is ISO 17573 Electronic Fee Collection—Systems architecture for vehicle-related tolling and ISO 12855 Electronic Fee Collection—Information exchange between service provision and toll charging. The European Union is working towards a common European interoperable system for tolling where road users have On Board Units (OBU) and a contract with one home toll operator enabling pan-European roaming where foreign toll charges are invoiced through the home toll operator. This is known as the EETS directive, Directive (2004/52/EC) of the European Parliament and of the Council of 29 Apr. 2004 on the interoperability of electronic road toll systems in the Community. Furthermore, the European Commission Decision (2009/750/EC) of 6 Oct. 2009 on the definition of the European Electronic Toll Service and its technical elements puts this into effect.
A satellite based road tolling system comprises three main physical elements. 1) The satellites 2) vehicles equipped with OBUs observing signals from the satellites and 3) a so-called back office.
The most typical use of such systems is for tolling, where each vehicle owner pays a certain fee for use of the road at passage of a zone border in a so-called cordon based tolling scheme. In general there are two kinds of errors encountered with the use of such systems, one being a false registration of a passage, the other being missed recognition of a passage that actually occurred. Additionally the detection may erroneously be attributed to a wrong location or a wrong time. All errors may result in lower user confidence in the system and increased operational costs.
EP2230644A1 teaches a method and system which involves maintaining global positioning systems (GPS) of vehicles in standby. Positioning functions of the global positioning systems are stimulated at the proximity of geographical positioning points e.g. taxation points, where the stimulation of the positioning function of each global positioning system is calculated from an origin positioning instant, near geographical positioning point and maximum speed of the vehicles.
WO2010098128A1 describes a road passage charging system which charges a toll for vehicles which run a road in a predetermined segment and are equipped with a position detection section which detects the position of a vehicle, a number of vehicles calculation section which calculates the number of vehicles present on a road in a predetermined segment from the positional information of vehicles detected by the position detection section, a traffic jam decision section which decides whether the road in the predetermined segment is congested or not by comparing the number of vehicles calculated by the number of vehicles calculation section with the predetermined threshold, a charging segment setting section which sets the predetermined segment as a charging segment when a decision is made that the predetermined segment is congested by the traffic jam decision section, a charging segment information delivery section which delivers information indicating that the predetermined segment set by the charging segment setting section is the charging segment, and a charging section which charges a toll for vehicles which run the road set as the charging segment.
EP1708143A2 describes a system including an onboard unit mounted in a vehicle to acquire position-related data of the vehicle. A central and stationary back office processes the position-related data to generate normalized position data. A service unit processes the normalized position data. The onboard unit and back office have interfaces to enable data exchange.
EP1657683A2 teaches a method by which a received position signal is transferred to a receiver system with a computer unit which has a digital map stored in a memory. At least one area (e.g. country) is defined in relation to the map in the computer unit, and is bounded by at least one polygon curve. The region of the area is selected so that the types of recognition used within the area are the same, and are different from the types of recognition used in further, adjacent areas.
U.S. Pat. No. 7,324,017B2 describes a process for determining travel through at least one toll road section by at least one vehicle by means of a position determination system which is set up to determine the current position of at least one vehicle, whereby positions of the at least one vehicle are compared with the position of at least one reference point characteristic for an entrance to a toll road section, whereby the orientation of the vehicle is determined within a specifiable region about the entrance, whereby it is determined whether the orientation determined agrees within a specifiable tolerance range with the orientation characteristic of entry onto the toll road section.
US patent application No. 2011/0153267 A1 describes a tracking unit for use with a location based service system. The location tracking unit comprises a navigation receiver adapted to implement a location tracking function, data processing means adapted to determine an occupied location according to a first location matching process. The first location matching process uses navigation data from the navigation receiver and a first set of geographical data, and data processing means adapted to verify the integrity of the first location matching process based on a second location matching process using navigation data and a second set of geographical data.
DE 1015 5501 A1 teaches a method for satellite based vehicle passage detection by use of mathematically defined polygons. The reliability of the detections is assumed to be increased by assessing the duration of each vehicle in a tolerance zone surrounding the zone to be monitored.
US 2009157566 A1 teaches a method addressing the problems of: a) generating a tollpath of consistent length by determining one of a possible set of paths which are all the same length in cell-count every time the same journey is taken, b) determining a consistent price for each tollpath by setting pre-determined values on those cells such that every possible path variant of a specific journey produces the same toll, and c) determine the correct price for each tollpath by adjusting prices in each cell to account for the exact distance actually represented, so that the toll calculated exactly matches the toll that would be calculated had the exact linear distance been measured on the actual road.
In spite of the teachings mentioned above there is still a need for improved methods and systems for zone based detection of objects, such as vehicles, passing into and out from a geographical zone, providing improved reliability and reduced risk of false crossing assessments.